Environmental Engineering Reference
In-Depth Information
focus the sun's rays, using mirrors, to heat a water, oil, or molten salt
to about 750°F and use it to drive a turbine to generate electricity. As a
source of large-scale power, CSP is less expensive and more practical
than photovoltaic systems, not least because the technology can deliver
power for hours after the sun sets or the day is cloudy by keeping the
hot fl uid in insulated tanks.
52
America's southwestern deserts are an abundant source of sunshine
that could meet the country's power needs several times over if it were
full of CSP equipment (fi gure 7.5).
53
CSP is still expensive at 12 cents
per kilowatt-hour but the cost is falling as the technology improves and
cost-reduction strategies are implemented, and is now half the price of
electricity produced by photovoltaic cells. In 2008, the Bureau of Land
Management received more than thirty planning requests to develop
large-scale CSP plants across the United States. In 2009 an Israeli
company signed an agreement with a California company to build the
world's largest solar thermal plant in California. The plant will generate
1,300 megawatts of electricity and generate 286,000 megawatt-hours per
year by 2013.
Although the cost of solar power appears to be much greater than
that of fossil fuels or nuclear energy, the numbers are deceptive because
of federal subsidies Congress has granted to the nuclear industry and the
Whr/sqm/day
Figure 7.5
Average daily solar radiation, 1961-1990. (National Renewable Energy Laboratory)
